This invention relates to the application of new nematic liquid crystal substances in electro-optical devices for the modulation of the incident or traversing light as well as for the representation of numerals, signs and images.
A wide variety of substances and mixtures for electro-optical components have already been proposed up to now (D. Demus in: Nonemissive Electro-optic Display, ed. by R. A. Kmetz and F. K. v. Willisen, Plenus Press, New York-London, 1976, P. 83-117; V. V. Titov, Proceed. 3rd Liquid Crystal Conference of Soc. Countries, Budapest 1978; G. Weber, P. del Pino, L. Pohl, Proceed. "10. Freiburger Arbeitstagung Flussigkristalle" 1980).
The further development of the components as well as their utilization in other fields of application requires the availability of substances, the qualities of which have to be increasingly improved and adjusted to special purposes. Therefore, to aid in the modification of these qualities, new compounds are required that are derived from new classes of liquid crystal substances.
Up to now the prior art has only disclosed 2-(4-n-alkoxybenzyldenamino)-phenanthrene, as well as some 8, 10-dihydrophenanthrenes with alkyl and acyl substituents as liquid crystal substances, (J. Conceill, J. Billard; J. Jaques: Chem. and Ind. (London) 1974, 615; J. Conceill, C. Crea, J. Billard, J. Jaques: Pramana Suppl. 1, 1975, 397). No processes for the manufacture of the substances of this invention have been disclosed up to now.
The object of this invention is nematic liquid crystal-substances with high clear points, low threshold voltage as well as sufficient supercooling ability in electrical fields for electro-optical devices as well as the processes for their production.